Although I think you can do it with just the existing block power switches (i.e. replacing one DC power pack with DCC) I agree with Martin that you need to be careful about not crossing from DC to DCC or vice-versa. When you first go to DCC and only have one or two DCC engines, it's tempting to mix them - have a DCC engine running a train on the main, while a DC engine switches in the yard, something like that. I'd advise NOT doing that - when going to DCC, get the DC engines off the layout, or on separate yard tracks where you can cut all power to them.
BTW I think all DCC decoders now (and for many years) are "dual mode", so once you convert them, you can still run them on DC. It works better for non-sound engines, because the DCC sound takes a lot of power on DC so there isnt' much left over for the motor.
Your biggest concern when connecting DCC is voltage drop. Possibly you will need to add some more feeders and/or increase the size of the longer wires leading fromn your block switches to each block. Best way to find out is to hook it up and try it out. Do the quarter test all over your layout once DCC is connected. Quarter test gets its name by using a coin or some piece of metal to short across the rails. Each time the rails are shorted, the booster should shut down immediatly. It should not delay not even for a second. If it does, add feeders to that area or increase teh wire size. Maybe even just solder some joiners together.
Connecting DCC to one of your cabs is the way I did it way back when. However, I don't recommend it. There is the chance that one or more of those blocks could be mistakenly connected to the DC power while the rest is running DCC. Some damage could result if an engine crossed from a DC block to a DCC block. Most cases the DCC system won't be damaged. It is made to shut down quickly for that short circuit. What can happen is increased voltage being fed to the engine or cars spanning the gap, It will get the whole DCC voltage as well as the DC voltage. Some motors, most lights, and a few brands of decoders (mostly expensive sound decoders) won't be able to handle the extra voltage. decoders shgould be able to take the extra decoders but some are not built to NMRA standards. You won't know which ones until it doesn't work anymore.
So the best way to connect DCC is to disconnect DC completely. This can be done with a double pole master switch or a simple plug.
As far as your switches... Basically if they work with DC they will work with DCC. DCC boosters are designed to shut down in the case of a short much faster than the average DC power supply. So if there is a brief short at a switch, the booster may trip. I've seen more of these troubles fixed by simply setting the wheels to the correct guage with an NMRA guage.
Martin Myers
Just in case you have not used a meter. I have four and are very adequate for model railroading.
http://www.trainelectronics.com/Meter_Workshop/index.htm
http://www.trainelectronics.com/Meter_HF/index.htm
My meters read about 13.6 VAC on the NCE Power Cab. The DC supply for the Cab is 13.9 DC so close enough for me. My Scope shows about the same.
If you want a cheap DCC ampmeter, make the below. Did one for the club with a 5 amp DCC systems. The system trips at about 4.97 amps the last I recall.
I have a high wattage rheostat that I use to simulate a load on the layout.
Use the 20 ma DC scale on the meter.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Balloon DudeThank you all very much for your input, I do appreciate it. A question concerning the frogs. How do I do know if they are plastic?
Touch the pair of probes to the ends of the frog to be tested.
Alton Junction
.
I believe the custom line is metal, but it may be pot metal and non magnetic. Assuming it's glued and ballasted and you can't tell by gently taping on it, I would use an exacto knive point and cut or scrape in a non obvious, non-functional spot and see if it cuts like plastic.
If it is metal/Atlas there are threads here about drilling/tapping it for a 1-72 screw so you can wire it.
Henry
COB Potomac & Northern
Shenandoah Valley
Agree with Andrew on buss wire size. As a rule buss wire gage in the 14-16 range is adequate, some will say 12 gage, some may use 18. In my view #20 or #22 gage wire is too light for a buss. Feeders, if they are not too long is a good use for the lighter wire.
I'm with the group that says "go for it". When I built my current layout, I divided it into blocks, with two cabs, and started out with DC. I eventually connected the DCC, and now the DC power pack is cab B and the DCC is cab A. NEVER try to run both at the same time time.
The one thing I can suggest, that I did, is to isolate both rails, and NOT use common rail. With both rails isolated, you should be good to go. You might have to add more feeders.
Mike.
My You Tube
I experienced the same results as Richard (Cowman) and Stix (wjstix). My initial layout was a switching layout with 16 blocks, a reverse loop at one end, two DC power packs and 50' of main line.
I replaced one of the power pack with a NCE PowerCab and everything went fine despite many sectional tracks.
I eventually replaced the wiring and soldered many rail joiners to conform to DCC good practices but this is another story.
As far as I am concerned, running trains on DCC rather than operating blocks was a good move.
Guy
Modeling CNR in the 50's
cowman My DC layout had seven blocks and was set up for two power packs. Attached the DCC where one power pack would have been. Threw all blocks to that one side and away the locos went. No significant problems with power, despite sectional track. No blocks were very long. Good luck, Richard
My DC layout had seven blocks and was set up for two power packs. Attached the DCC where one power pack would have been. Threw all blocks to that one side and away the locos went. No significant problems with power, despite sectional track. No blocks were very long.
Good luck,
Richard
You need DCC equiped locomotives or change the ones you have by installing DCC decoders. Leave the blocks connected to the layout for tracking down electrical problems in the future. I don't know why you have two controls on the layout. If one is the main and one is the yards you need to connect them both to the DCC system, but if they are attached to DPDT switches with a center off only connect one set of wires to the DCC system and cap the other wire set. You should check the turnout frogs to see if they are plastic. If they are plastic you can connect one set of track wires from your power supply to the DCC control unit per the instructions that came with the DCC system. It is best to disconnect all DC power from the track. The Atlas snap switch actuators, if the frogs are plastic, may be operated by the DC pack you have. If the atlas turnout frogs are not plastic they will require isolation before you connect the DCC system. If not sure about the frogs don't hook up the DCC unit and don't connect the snap switches actuators to DC until you confirm they are plastic. The frogs if they are not plastic they will cause a short. If the frog is plastic this is a short term way to see if you like DCC. The gentlemen that have answered you on this issue are right. You need to make the changes in the track connections to the DCC system and will need to add short protection as soon as possible. Please use a surge protection power supply, as the DCC system pc boards need to be protected like your computer. If the atlas turnout frogs are not plastic they will require isolation before you connect the DCC system. You can purchase a switch machine that will power the isolated frog and change the frog polarity to match the switch point position. You will like DCC. Good luck.
richg1998I use to run the NCE Power Cab with two amp limit which worked fine with #22 wire.
Thats not a good idea for most applications. While it does work, you have a high resistance between your power supply and track.
This can prevent the layout from shutting down in the event of a short circuit. Better to use a larger guage wire 14-16 for a main bus and 22 for short feeders only (wire lengths not to exceed 2ft).
Balloon Dude,
Suggest you take a look at the following sites for best practices for DCC wiring and what can happen if you skimp to much...
http://www.wiringfordcc.com/
https://sites.google.com/site/markgurries/
This is model railroading You will eventually have issues pop up. Part of the learning process when switching to DCC. Not unusual for many.
How many DC engines do you have? They can be converted by adding decoders, and there are people who will perform this service for you. It may be a simple board replacement plug-in, or may require some soldering. Basic decoders are easy, while sound decoders or installations with flashing ditch lights are harder.
If your trackwork is good, you will be OK for a while, but I'd suggest a bus-and-feeder arrangement to get more reliable power. If you have a lot of loose track joints, common with sectional track, it makes more feeders even more important. (This is true of DC as well.) You might also consider maintaining some of your block structure and dividing your layout into DCC power districts, each protected by its own circuit breaker.
You'll love it.
It takes an iron man to play with a toy iron horse.
Oh, it will work. Others have asked the same question here. Just never run a couple blocks in DC and some in DCC. Our club tried that and smoked a NCE 5 amp booster when a loco crossed a boundry. Old timers like to gab. lol.
Our club DC layout in the 1980's was wired with #24 telephone wire.
I use to run the NCE Power Cab with two amp limit which worked fine with #22 wire.
Try it and find out. Do you have a cross over or reverse loop on the layout? Those will require a reverser.
My home layout a little larger and wired with #22. Unplugged DC and plugged in DCC. Turned on all blocks. I use to only run two or maybe three locos so power was not an issue.
You can also use a DPDT switch.
Spots with intermittent pickup will show up. A few dirty rail spots for me. Turnouts are hand laid so no issues at turnout frogs.
Our club did the same but had to put in #16 buss. Bad spots will show up quickly with DCC.